Sheet metal can body



W. F. PUNTE SHEET ME'IAL CAN BODY Filed Sept. 30, 1936 Patented oer. 24, 1939 i 2,177,028

UNITED STATES PATENT OFFICE SHEET METAL CAN BODY William F. Punte, Syracuse, N. Y., assignoi' to Continental Can Company, Inc., New York. N. Y., a corporation of New York Application September 30, 1936, Serial No. 103,434

7 I v 1 Claim. (01. 220-76) This invention relates to new and useful im-' In accordance with the invention, the body provements in a sheet metal can body, and parblank ID, as shown in Figs. 1 and 2, has corner ticularly in the solder bonded side seam thereof. notches I i cut in one end of the blank and the In using cans for the packaging of certain liqportion of the blank between these notches is uids, such as beer for example, it is a common folded in opposite directions on the lines [2 and practice to heat the contents of the can for the I3 to form a double hook consisting of an outer purpose of sterilizing it, after the can is sealed, face I4, an intermediate web l5 and an inner and this develops a very high internal presure. face I6, the terminal edge I! being somewhat It is highly important, therefore, that a can used beyond the fold line 12.

for this purpose should have a very strong side A series of slits l8 are cut along the fold line seam. I 12, preferably before the folds are made. At the Since the pressure of the liquid is exerted equalopposite end of the blank, the corners are mily in all directions, the net result is that the tered or tapered, as at l9, and in the tongue strain imposed on the side seam is chiefly tanportion 20 between these tapered corners, a segential. In a can having a side seam with the ries of longitudinal slits or kerfs 2| are cut. 15

usual interengaging hooks, the tangential strain The blank, as thus formed, is bent to a cylintends to unfold the hooks and this tendency imdrical shape, the tongue portion 20, which conposes a direct tensile stress upon the solder bond stitutes the inner side of the seam, is seated between the contacting faces of the hooks, which within the fold l3, and the seam is then bumped often ruptures the bond. to the shape shown in Fig. 5. It will be noted 30 The lap seam offers more resistance to tangenthat the base 22 of the tongue portion 20 is bent tial strain than a seam having interengaging part way around the fold l2 leaving a recess 23 hooks because the stresses imposed on the solder to which the molten solder is applied. The porbondare of a shearing character. The side seam tion of the side l6 which extends beyond the 25 is usually formed by lapping one edge portion fold I2 is also bent in a similar manner, as shown 25 of the blank on the other edge portion thereof at 24, thus forming a retaining member which and applying solder between the contacting faces. holds the tongue 28 firmly seated in the fold l3 The solder bond is limited by the width of the while it is being soldered. The outside of the lapping sections; that is, the extent of the solder can body thus presents a continuous uniform cy- 3 bond is determined by the width of the side lindrical surface with no raw edge. 30 seam. In bringing the ends of the blank together, it An object of the present invention is to prowill be understood that the corner portions are vide a side seam for metal can bodies, wherein lapped as shown in Fig. 6, the edges I9 being the edge portions of the body blank are lapped tapered in order to facilitate the subsequent 5 so that the solder bond is subjected to a shearing flanging of the ends of the body, a d t e addistress and wherein th t d parts ar shaped tion of the end closures to the can in a manner so as to hold the parts engaged during solder which is Well known. bonding As the solder is applied in the usual manner The distinctive features of the invention and to the recess 3, i ws by capillary t ra n 4 the advantages thereof will be more specifically all p s Of the Seam. A portion of it flows 4 explained in connection with the accompanying between the side [5 and the tongue 0 d thence drawing, in which: on the other side of the tongue 20 to the extreme Fig. 1 is a plan view of the can body blank end of the side 15, the slits 2| being provided to with one end folded, prior to bending the blank to p v p l pp of e gases n dama cylindrical form. ming 0f the solder by the pinching of the end 45 Fig, 215 a side e1evati0n 0f the sam of the tongue in the fold I3. Another portion Fig. 3 is an elevation of the seam after it is of the solder flows through the slits I8 and bebumped, as viewed from the inside of the can tween the sides l4 and I5 of the fold l2. body. It will be apparent that a side seam construct- Fig. 4 is an elevation of the same, as viewed ed as above described is exceptionally strong. 50 from the outside of the can body. I There is a solder bond on both sides of the tongue Fig. 5 is an enlarged section taken on the line 20, which affords double the strength of the 55 of Fig. 4. usual lap seam. This is further reinforced by Fig. 6 is an enlarged section taken on the a solder bond with the curved extension 24 of line 6-6 of Fig. 4. the side IS. The tangential strain set up by in- 55 ternal pressure in the can develops only a shearing strain on this bond, against which the solder bond is most effective. There is substantially no tendency for the sides of the seam to hinge about the fold. lines and thus rupture the solder bond between them by tensile stress, as in the case of interlocking hooks. The seam offers the utmost resistance against external knocks, as well as internal pressure.

It will be'noted from the above thatt'he solder bond uniting the edge portions of the body blank extends more than twice the distance that the edge portions are lapped. This increases the strength of the side seam without unduly increasing the width of the side seam.

It will also be noted that the bending of the metal parts adjacent one edge of the side seam not only greatly facilitates the handling of the body during soldering but also increases to a considerable extent the solder bond uniting the edge portions. By the improved construction of side seam described, where the folded parts are on the interior of the can body, the exterior of the can body is of uniform diameter throughout. which has many advantages.

7 It will, of course, be understood that the details herein shown and described are for the purpose of illustration only and that the invention also includes all such modifications as mayfall within the scope of the appendedclaim.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:v I

A sheet metal can body having a solder bonded side seam, one edge portion of the body being folded back upon the inner face of the body wall and reversely folded so as to extend beyond the first fold, said reversely folded portion being spaced away from the first-named folded portion so as to receive thei'ebetween the other edge portion of the body wall, and said extended portion being bent outwardly so as to hold the last-named edge portion of the body wall in between the folded back portions, said body wall having slits formed therein at the first-named fold so as to permit the solder to flow by capillary attractionbetween the body wall and the first-named folded back portion, and said secondnamed edge portion of the body wall having slits formed therein extending at an angle to the edge for permitting the solder to flow by capil' lary attraction so as to solder bond the inner faces of both of the folded back portions to said edge portion of the body wall.

.WILLIAM F. PUNTVEQY 

